Hi Grant- Welcome to the Coins and Canada website. You say the four notes you have are graded GUNC. I take it then they have been certified. To answer your questions, the OS Prefix notes have a book value of $4.00 each in GUNC. As far as sequential notes , on modern notes there is very little if any...

First of all, welcome to the Forum. To answer some of your questions, unless it is a rare coin, condition means everything in regards to the value. If most of your newer silver coins are worn, they would only be worth bullion value. As far as your "special" coins, your 1990 bare belly nick...

I don't think in this case it would make much difference.Your coin has quite a few dings and scratches so one more shouldn't make too much difference.Besides, it is the Obverse that is used for grading, not the reverse.

As far as I know, there is no such thing as an EWL on any year Canadian Silver Dollar.I have seen some listings claiming an EWL under the canoe, but that is part of the design. Exactly where is the seller claiming the EWL is?

It is not an error and has nothing to do with mintage.It has taken a hit from something.You can see where the metal has been pushed aside.It's called PMD. (Post Mint Damage)But welcome to the site and feel free to ask more questionsif there is anything you are unsure of.